FI78020B - BARKPRESS. - Google Patents

Description

78020

The present invention relates to a bark press for increasing the dry matter content of wet bark generated during peeling of wood, wherein the bark press has a water-permeable abutment surface and , that in the final stage of drying the compression is higher than in the initial stage, the abutment surface 10a being formed by a rotating surface whose axis of rotation is substantially vertical and the individual points of the axis of the press rolls remain in a trajectory substantially perpendicular to the axis of rotation of the abutment surface.

The bark generated in wood debarking is used almost alone-15 as its own fuel. However, the dry matter content of the shell is usually so low that it must be drained before it is technically possible and economically viable to burn it.

At present, various presses are used to remove water, such as a piston press, external roller presses or internal roller presses, in which the shell passes through a drain formed by a draining, pressing roller formed one or more times.

However, current devices have e.g. the following disadvantages: In the piston press, there is a lot of wear, water gets from the wet shell to the shell that has already been pressed dry, and the water does not drain vertically downwards.

In a roller press, where the shell passes only once through the jaw, the pressure in the jaw must be very high, making it difficult to feed the 30 wet husks to the jaw. In addition, if the gut opens due to some foreign object, the final dry matter content will decrease.

In a roll press in which the shell passes several times through the same die, it is difficult to adjust the load on the die so that it would be suitable for different stages of the process where the shell has a different dry matter content. Another disadvantage of the roller press is that some of the water removed from the shell is returned to the shell.

The object of the present invention is to provide a shell press 2,78020 which has been deactivated by the operation of existing presses e.g. the above disadvantages. The shell press according to the invention is characterized in that the press rolls are arranged so that their distance from the axis of rotation of the abutment surface changes as they move from the feed point to the exit point, and that machine members are arranged on the abutment surface between the rollers. to the roll and mix it between the rollers.

The shell press according to the invention has the following advantages: 1. The shell is pressed several times, always using a suitable pressing pressure.

2. In a dewatering member, e.g. a perforated plate, a perforated surface corresponding to the amount of water discharged can always be used, i.e. when the shell is wet and the pressing surface is small, the perforated surface is large and vice versa.

3. The shell is mixed between different compression steps to facilitate dewatering.

4. Water always drains down from the shell and cannot get back into the shell.

The invention will be described mainly in the following with reference to the accompanying drawings:

Fig. 1a shows a piston press Fig. Ib shows an external roll press Fig. 1a shows an inner roll press 25 Fig. 2a shows a top view of a shell press according to the invention

Figure 2b shows a side view of a press according to the invention

Figures 2c and 2d show the geometry of a shell press according to the invention.

The previously known hydraulic shell press of Fig. 1a has a press chamber 23 formed by a perforated base plate 21, perforated side plates and a base plate of the press beam 22. At the top of the press is a shell feed hopper 24.

35 A piston 25 perforated at its front surface pushes the shell coming from the hopper 24 into the compression chamber 23. During the pressing step, the water leaving the shell exudes through the above-mentioned perforated surfaces. The compression beam 22 and the piston 25 derive their compressive forces from the hydraulic cylinders 26 and 27.

78020

The previously known press according to Fig. Ib has two opposite rollers 28, between which water is squeezed out of the shell as it passes through the groove.

In the previously known press-5 according to Fig. 1, the press roll is arranged inside the cylinder 30. The shaft of the cylinder is tilted and the shell is repeatedly exposed to the friction between the roll and the cylinder.

The shell press according to the present invention (Figures 2a and 2b) has a water-permeable abutment surface 1. The abutment surface 10 has the shape of a rotating surface, the axis of rotation 5 of which is e.g. vertical. Surface 1 can be, for example, a plane, a cone or a spherical surface. On the surface 1 there are loaded rollers 2, which can be, for example, cylindrical or conical or double-conical or concave. Preferably, the direction of the axis 15 of the rollers 2 is such that the axis is flush with the radius of the abutment surface. The number of rollers can be e.g. 4-7. The surface 1 and the rollers 2 have a relative movement with each other such that a single point 7 in the axis of the rollers 2 remains in the path of movement 3, which is generally perpendicular to the axis of rotation 5 of pin -... 20 nan 1 (see Figures 2c and 2d).

The movement is achieved, for example, by rotating the position 1. Alternatively, the rollers 2 may be movable and the surface 1 in place.

The movement causes the shell to get between the surface 1 and the rollers: 25 2. In addition, the rollers may be equipped with their own drive 3 · The shell is guided to a suitable location on the surface and during rotation its distance from the axis of rotation either increases, decreases or remains the same. The dry shell is removed from a suitable location on surface 1. Preferably, the shell is fed 30 in the vicinity of the center of surface 1 and removed from the edge of surface 1, passing along surface 1 along a helical path. The water leaving the shell passes through the surface 1 below it, from where it is discharged in a suitable manner.

'... · To enhance drying, there may be 35 members Ί between the rollers, e.g., scrapers that guide the shell to the next roll and mix the shell between different presses * 78020. The last scraper guides the shell off the surface 1. The position of the scrapers can be adjustable.

The compression of the rollers 2 can be different so that a higher compression 5 is used in the final stage of drying than in the initial stage. Likewise, the perforation of the surface 1 can vary in the radial direction so that e.g. when the shell is fed to and removed from the middle part of the surface 1, the perforation is denser in the middle part of the surface, i.e. at the beginning of drying than at the edges.

Claims (8)

78020 A bark press for increasing the dry matter content of wet bark generated in wood peeling, the bark press having a water-permeable abutment surface (1) and 5 loaded press rolls (2) to be pressed against the abutment surface, arranged above the abutment surface and having axes relative to the abutment surface compression is. . different in that at the end of the drying the compression is - - greater than at the initial stage, the abutment surface being formed by a rotating surface (1) whose axis of rotation (5) is substantially vertical and the individual points (7) of the axis of the compression rollers (2) remain in the trajectory (8), is substantially perpendicular to the axis of rotation of the abutment surface (5), characterized in that the pressing rollers (2) are arranged so that their distance from the axis of rotation (5) of the abutment surface (1) changes as they move from the feed point to the exit point, and machine members (4) are arranged between the rollers (2), which guide the shell from the previous roll to the next roll and mix it 20 between the rollers. Shell press according to Claim 1, characterized in that the distance of the press rolls (2) from the axis of rotation (5) of the abutment surface (1) increases when moving from the feed point of the shell to the exit point. Shell press according to Claim 2, characterized in that the perforation of the abutment surface (1) is denser in the central part of the abutment surface than at its edges. Shell press according to one of Claims 1 to 3, characterized in that the one or more press rolls (2) are provided with a drive device (3). Shell press according to one of Claims 1 to 4, characterized in that the press rolls (2) are cylindrical. Shell press according to one of Claims 1 to 5, characterized in that the shell-guiding elements (4) are scrapers. Shell press according to Claim 6, characterized in that the last scraper (4) is arranged so as to guide the shell away from the abutment surface (1). Shell press according to Claim 6 or 7, characterized in that the position of the scrapers (4) is adjustable.